From patchwork Wed Feb 28 19:18:27 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nayna X-Patchwork-Id: 10249391 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 3BD7060594 for ; Wed, 28 Feb 2018 19:19:17 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2632D28DB1 for ; Wed, 28 Feb 2018 19:19:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1B14528DD0; Wed, 28 Feb 2018 19:19:17 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C0EFF28DD4 for ; Wed, 28 Feb 2018 19:19:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933549AbeB1TSz (ORCPT ); Wed, 28 Feb 2018 14:18:55 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:48562 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933352AbeB1TSx (ORCPT ); Wed, 28 Feb 2018 14:18:53 -0500 Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w1SJFI65090155 for ; Wed, 28 Feb 2018 14:18:52 -0500 Received: from e06smtp10.uk.ibm.com (e06smtp10.uk.ibm.com [195.75.94.106]) by mx0b-001b2d01.pphosted.com with ESMTP id 2gdxbum0xs-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 28 Feb 2018 14:18:52 -0500 Received: from localhost by e06smtp10.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Wed, 28 Feb 2018 19:18:47 -0000 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w1SJIlH444957900; Wed, 28 Feb 2018 19:18:47 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C376C11C050; Wed, 28 Feb 2018 19:11:39 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A092D11C04A; Wed, 28 Feb 2018 19:11:38 +0000 (GMT) Received: from localhost.endicott.ibm.com (unknown [9.60.15.245]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 28 Feb 2018 19:11:38 +0000 (GMT) From: Nayna Jain To: linux-integrity@vger.kernel.org Cc: zohar@linux.vnet.ibm.com, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, peterhuewe@gmx.de, jarkko.sakkinen@linux.intel.com, tpmdd@selhorst.net, jgunthorpe@obsidianresearch.com, patrickc@us.ibm.com, Nayna Jain Subject: [PATCH 2/3] tpm: reduce poll sleep time between send() and recv() in tpm_transmit() Date: Wed, 28 Feb 2018 14:18:27 -0500 X-Mailer: git-send-email 2.13.3 In-Reply-To: <20180228191828.20056-1-nayna@linux.vnet.ibm.com> References: <20180228191828.20056-1-nayna@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18022819-0040-0000-0000-000004191E60 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18022819-0041-0000-0000-0000261C1F6A Message-Id: <20180228191828.20056-2-nayna@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2018-02-28_11:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1802280234 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP In tpm_transmit, after send(), the code checks for status in a loop with polling every 5msec. It is expected that the tpm might return earlier than 5msec, so it might be adding to unnecessary delay. This patch reduces the polling sleep time from 5msec to 1msec. After this change, performance on a TPM 1.2 with an 8 byte burstcount for 1000 extends improved from ~14sec to ~10.7sec. Signed-off-by: Nayna Jain --- drivers/char/tpm/tpm-interface.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index 76df4fbcf089..2d22f981f0c9 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -470,7 +470,7 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space, goto out; } - tpm_msleep(TPM_TIMEOUT); + tpm_msleep(TPM_TIMEOUT_POLL); rmb(); } while (time_before(jiffies, stop));